The Premier 4KV EXCEL Voltage Stabiliser is also equipped with fail safe circuit protection feature. This ensures that on the event of a component failure, the stabiliser cuts off power to a connected appliance to limit any further damage., The Premier 4KV EXCEL Voltage Stabiliser is equipped with controlled synchronized switching technology that protects the connected appliances well against any sudden current surges. The stabiliser has an 185-265V working range.